Memory on graphics cards

[thestepster]

well me and alienalx were talking not gonna go down on how it came about but we were talkin about sli

so here's the question, in sli does the memory of both cards get used? or does only the top mem get used? then this moves onto question 2 if the memory on the top card only gets used where does dual gpu cards stand in this? 4gb 6990 and 3gb 590 does this mean only 2gb and 1.5gb? or does it all work since its on the same pcb?

 

[kilobravo]

If using multiple screens amd 6970 2gb x3, beats nvidia gtx580 1.5gb x3 by a large margin.

Also 6950 1gb vs. 6950 2gb,both in x-fire on 3 screens,the 2gb version beats the 1gb by a large margin.

Conclusion must be the amount of rams used.

 

[thestepster]

yeah i can see there being a difference but that still isnt showing if the cards are running 4gb or 2gb in xfire or just the memory of the top card

 

[wotevajjjj]

im not sure, but i think it only uses 1 cards memory if you only connect a screen to one card but if the amount of ram you need to fill up multiple screens, it uses both ram

 

[kilobravo]

Did some sweeping around,to find some info about it,but nothing came out of that.

But the conclusion must be,that amd is better to utilize the rams,than nvidia gpu`s,in multiple gpu setup and 3 screen resolution.

From single gpu to xfire or sli,amd gpu`s is scaling a lot better than nvidia gpu.

Maybe its the answer,why 6990 4gb is faster than 590 3gb?

 

[thestepster]

yeah memory difference at high resolutions is deffo the big factor in performance differences and this is how im curious cause there literally isnt anything out there with solid info on this wonder if nvidia would answer it lol

 

[kilobravo]

Maybe its implementing physx and cuda cores,that cuts nvidia gpu`s in high resolution,and why they dont utilizes rams in sli.

Im sure nvidia wont answer that question

 

[thestepster]

im pretty sure ram not gettin used isnt just an sli thing but the whole thing about moer screens higher res and stuff is a valid point but having that extra memory even at 1080p would be awsome

 

[kilobravo]

That would be very nice,but as long nvidia is blistering,farking fast and beats amd in every single amd vs. nvidia gpu,single sceen setup,thats not going to happen,i think.

Multi-screen in high res,is only for a few pro and enthusiast gamers.

 

[DragonPC]

The memory is actully mirrored in sli/cfx

 

[JezEngland]

ye. You could use MSI Afterburner to see the result. The system uses an equal amount for each memory unit

 

[marsey99]

the ram gets used on all cards but they have the same info as they are rendering the same stuff, as epic said its like its mirrored.